Measles outbreak spreads across anti-vaccine ‘hotspot’ in Washington

BIG THINK – Stephen Johnson – 24 January 2019 – A measles outbreak has spread across an anti-vaccination “hotspot” in Clark County, Wash., causing officials to declare a public health emergency.

The outbreak has infected at least 25 people so far, including 18 children between the ages of 1 and 10, according to a government release last updated on January 24. At least one person has been hospitalized. Officials are prohibiting students and staff without documented immunity from entering schools identified as possible exposure sites.

The outbreak occurred about 25 miles north of Portland, Oregon, in Clark County, an area known for its low rate of immunization. In an interview with the Washington Post, Peter J. Hotez, a professor of pediatrics and dean of the National School of Tropical Medicine at Baylor College of Medicine in Houston, described the county as a “hotspot” for outbreaks.

“This is something I’ve predicted for a while now,” he said about the outbreak. “It’s really awful and really tragic and totally preventable.”

About 8 percent of children in Clark County were exempt from getting the vaccinations required to enter public school kindergarten in the 2017–2018 school year. The majority of those kids had received exemptions for personal or philosophical reasons. An increasing number of American public school students have been granted these so-called non-medical exemptions in recent years, which are currently allowed in 18 states. A 2018 study found that Portland had one of the highest numbers of kindergartens who had received such exemptions.

“Portland is a total train wreck when it comes to vaccine rates,” Hotez told the Post.

In parts of Oregon and Washington, these exemptions have almost surely helped to push local populations outside of what’s known as herd immunity — the level of immunization that needs to occur in a population in order to prevent the spread of a contagious disease. A 2018 analysis conducted by The Oregonian estimated that some 65 percent of Oregon’s public charter schools lack herd immunity, and that a much smaller yet still significant number of public schools lack herd immunity.

Clark County officials wrote that “measles is extremely contagious. The virus travels through the air and can stay up to two hours in the air of a room where a person with measles has been… Measles is so contagious that if one person has it, 90 percent of the people close to that person who are not immune will also become infected.”